Substrate processing apparatus and article manufacturing method

ABSTRACT

The present invention provides a substrate processing apparatus that processes a substrate, the apparatus including a stage configured to hold and move the substrate, a conveying unit configured to hold and convey the substrate between conveying unit and the stage, an accumulation unit configured to accumulate control information concerning the stage and the conveying unit which is generated by processing the substrate, and a determination unit configured to determine a conveying procedure when conveying the substrate between the stage and the conveying unit by selecting one of a plurality of conveying procedures which can be set for the stage and the conveying unit based on control information accumulated in the accumulation unit.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a substrate processing apparatus and anarticle manufacturing method.

Description of the Related Art

With an increase in the variety of device manufacturing methods(processes) using exposure apparatuses, it is necessary to conveyvarious types of substrates with high productivity (at high speed). Thevarious types of substrates include, for example, a substrate with alarge amount of warpage, a substrate having a reverse surface with lowflatness, and a substrate having a reverse surface coated with achemical agent or coating agent.

Japanese Patent Laid-Open Nos. 2006-269867 and 2017-108169 proposetechniques concerning the conveyance of substrates. Japanese PatentLaid-Open No. 2006-269867 discloses a technique of conveying substrateswith high productivity by changing drive parameters of the respectiveunits of a conveying mechanism, the pressure (substrate chuckingpressure) with which a substrate is chucked, and the like. JapanesePatent Laid-Open No. 2017-108169 discloses a technique of conveyingsubstrates with high productivity by using dual conveying paths forsubstrates.

None of the conventional techniques is a technique that canautomatically determine (select), on the apparatus side, optimal driveparameters, a substrate chucking pressure, a conveying path, and thelike for each process with respect to various types of substrates.

According to Japanese Patent Laid-Open No. 2006-269867, it is necessaryto provide a unit for measuring the amount of warpage of a substrate orgrasp the amount of warpage of a substrate in advance. In addition,according to Japanese Patent Laid-Open No. 2006-269867, drive parametersof the respective units of the conveying mechanism and a substratechucking pressure are determined from the amount of warpage of asubstrate, but there is no consideration to the state of the reversesurface of the substrate. On the other hand, the technique disclosed inJapanese Patent Laid-Open No. 2017-108169 needs to provide two conveyingpaths (first and second conveying paths) in order to improve theproductivity of substrate conveyance.

SUMMARY OF THE INVENTION

The present invention provides a substrate processing apparatusadvantageous in determining a conveying procedure when conveyingsubstrates.

According to one aspect of the present invention, there is provided asubstrate processing apparatus for processing a substrate, the apparatusincluding a stage configured to hold and move the substrate, a conveyingunit configured to hold and convey the substrate between conveying unitand the stage, an accumulation unit configured to accumulate controlinformation concerning the stage and the conveying unit which isgenerated by processing the substrate, and a determination unitconfigured to determine a conveying procedure when conveying thesubstrate between the stage and the conveying unit by selecting one of aplurality of conveying procedures which can be set for the stage and theconveying unit based on control information accumulated in theaccumulation unit.

Further aspects of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the arrangement of an exposureapparatus according to one aspect of the present invention.

FIG. 2 is a schematic plan view showing the arrangements of a substratestage and a conveying unit.

FIG. 3 is a flowchart for explaining the operation of the exposureapparatus.

FIGS. 4A and 4B are flowcharts for explaining the details ofdetermination processing (step S112) shown in FIG. 3.

FIG. 5 is a flowchart for explaining a productivity-oriented procedure.

FIG. 6 is a flowchart for explaining a stability-oriented procedure.

FIG. 7 is a flowchart for explaining a conveying procedure prioritizingproductivity at the time of the conveyance of substrates.

FIG. 8 is a flowchart for explaining a conveying procedure prioritizingstability at the time of the conveyance of substrates.

FIG. 9 is a view showing an example of a setting screen as a userinterface.

FIG. 10 is a view showing an example of a setting screen as a userinterface.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe attached drawings. Note, the following embodiments are not intendedto limit the scope of the claimed invention. Multiple features aredescribed in the embodiments, but limitation is not made an inventionthat requires all such features, and multiple such features may becombined as appropriate. Furthermore, in the attached drawings, the samereference numerals are given to the same or similar configurations, andredundant description thereof is omitted.

FIG. 1 is a schematic view showing the arrangement of an exposureapparatus 1 according to one aspect of the present invention. Theexposure apparatus 1 is a lithography apparatus used in aphotolithography process as a manufacturing process for a device, andprocesses substrates. In this embodiment, the exposure apparatus 1 isimplemented as a substrate processing apparatus that forms patterns onsubstrates. The exposure apparatus 1 exposes a substrate via a mask(original) by a step-and-scan system or step-and-repeat system andtransfers a mask pattern onto the substrate.

Note that the present invention does not limit the substrate processingapparatus to an exposure apparatus and may also be applied to an imprintapparatus and a drawing apparatus. In this case, the imprint apparatusbrings an imprint material supplied onto a substrate into contact with amold, and applies curing energy to the imprint material to form apattern on the cured material onto which a mold pattern is transferred.The drawing apparatus forms a pattern (latent image pattern) on asubstrate by drawing on the substrate with a charged particle beam(electron beam) or laser beam. In addition, the present invention can beapplied to apparatuses configured to process substrates, such as varioustypes of high-precision processing apparatuses and various types ofhigh-precision measurement apparatuses.

The exposure apparatus 1 includes an illumination optical system 104that illuminates a mask 109 with light from a light source 101, aprojection optical system 110, a first drive unit 112, a second driveunit 113, a substrate stage 116, a laser interferometer 118, and a thirddrive unit 119. The exposure apparatus 1 further includes an alignmentmeasurement system 124, a focus measurement system 140, a main controlunit 103, an illumination system control unit 108, a projection systemcontrol unit 114, a stage control unit 120, and a conveying unit 130.

The light source 101 emits (outputs) light in a plurality of wavelengthbands as exposure light. The illumination optical system 104 furtherincludes a shaping optical system (not shown) and an optical integrator(not shown). The illumination optical system 104 further includes alight-shielding plate 105, a half mirror 106, and a photosensor 107.

The light emitted from the light source 101 and entering theillumination optical system 104 is shaped into a predetermined shape viathe shaping optical system. The light shaped by the shaping opticalsystem enters the optical integrator. The optical integrator forms manysecondary light sources for illuminating the mask 109 with a uniformilluminance distribution. The light-shielding plate 105 is arranged onthe optical path of the illumination optical system 104 to form anarbitrary illumination region on the mask. The half mirror 106 isarranged on the optical path of the illumination optical system 104 toreflect (extract) part of light (exposure light) illuminating the mask109. The photosensor 107 is arranged on the optical path of lightreflected by the half mirror 106 to detect the intensity (exposureenergy) of the light. The illumination system control unit 108 controlseach unit (for example, the light-shielding plate 105) of theillumination optical system 104 under the control of the main controlunit 103.

The mask 109 has a pattern to be transferred onto a substrate 115, thatis, the circuit pattern of a semiconductor device, and is illuminated bythe illumination optical system 104. The projection optical system 110is formed from, for example, a refractive system or catadioptric system.The projection optical system 110 projects (forms) a pattern (its image)of the mask 109 onto the substrate 115 (one shot region of the substrate115) coated with a photoresist (photosensitizing agent) at apredetermined magnification (for example, 1/2). The projection opticalsystem 110 includes an aperture stop 111. The aperture stop 111 isarranged in the pupil plane of the projection optical system 110, thatis, a Fourier transform plane corresponding to the mask 109, andincludes an almost circular opening portion.

The first drive unit 112 includes a motor and sets a predetermined NA(numerical aperture) by controlling the diameter of the opening portionof the aperture stop 111. The second drive unit 113 drives (moves) anoptical element constituting part of the lens system of the projectionoptical system 110 along the optical axis of the projection opticalsystem 110. This makes it possible to suppress degradation inaberrations of the projection optical system 110 and reduce a distortionerror while properly maintaining the projection magnification. Aprojection system control unit 114 controls the respective units of theprojection optical system 110 (the aperture stop 111 and the opticalelements) via the first drive unit 112 and the second drive unit 113under the control of the main control unit 103.

As described above, the substrate 115 is a substrate onto which thepattern of the mask 109 is transferred (projected) and a photoresist isapplied. The substrate 115 includes a wafer, a glass plate, and othertypes of substrates.

The substrate stage 116 is a stage that holds the substrate 115. Thethird drive unit 119 moves the substrate stage 116 in three-dimensionaldirections, that is, a direction (Z direction) along the optical axis ofthe projection optical system 110 and a plane (X-Y plane) orthogonal tothe direction. The third drive unit 119 includes a motor for moving thesubstrate stage 116. In this embodiment, the direction along the opticalaxis of the projection optical system 110 is the Z direction (Z-axis),and the directions orthogonal to the optical axis of the projectionoptical system 110 are the X direction (X-axis) and the Y direction(Y-axis).

The laser interferometer 118 detects the distance to a mirror 117 fixedto the substrate stage 116 to measure the position of the substratestage 116 in the X-Y plane. The alignment measurement system 124measures a positional shift between the substrate 115 and the substratestage 116. The stage control unit 120 moves the substrate stage 116 to apredetermined position in the X-Y plane via the third drive unit 119based on the measurement result obtained by the laser interferometer 118and the measurement result obtained by the alignment measurement system124 under the control of the main control unit 103.

The focus measurement system 140 includes a projection optical system121 and a detection optical system 122, and measures the position of thesubstrate 115 in the direction along the optical axis of the projectionoptical system 110, that is, the height of the surface of the substrate115. The projection optical system 121 projects light (non-exposurelight) that does not sensitize the photoresist applied on the substrate115 and focuses the light at each position on the substrate 115. Thelight reflected at each position on the substrate 115 enters thedetection optical system 122.

The detection optical system 122 has a plurality of light-receivingelements for position detection arranged in correspondence with lightreflected at each position on the substrate 115. More specifically, theplurality of light-receiving elements for position detection arearranged such that the light-receiving surface of each light-receivingelement is almost conjugate to each position (each reflection point) onthe substrate 115 via an imaging optical system. Accordingly, thepositional shift of the substrate 115 in the direction along the opticalaxis of the projection optical system 110 is measured as the positionalshift of light entering each light-receiving element arranged on thedetection optical system 122.

The conveying unit 130 is a conveying mechanism for holding andconveying the substrate 115 between the conveying unit 130 and thesubstrate stage 116. As shown in FIG. 2, the conveying unit 130 includesa conveying port 201, a first substrate hand 202, a pre-alignment unit203, and a second substrate hand 204. The details of the conveying unit130 will be described later together with the conveyance of thesubstrate 115 between the substrate stage 116 and the conveying unit130. FIG. 2 is a schematic plan view showing the arrangements of thesubstrate stage 116 and the conveying unit 130.

A storage unit 123 stores various types of programs, data, and the likerequired to operate the exposure apparatus 1. In this embodiment, thestorage unit 123 also functions as an accumulation unit that stores andaccumulates control information concerning the substrate stage 116 andthe conveying unit 130 which is generated as a result of processing thesubstrate 115 in the exposure apparatus 1. In this case, the controlinformation includes holding forces with which the substrate stage 116and the conveying unit 130 hold the substrate 115 and the times requiredfor the substrate stage 116 and the conveying unit 130 to hold thesubstrate 115 with preset holding forces. In addition, the controlinformation includes measurement values concerning the alignment of thesubstrate 115 when it is conveyed between the substrate stage 116 andthe conveying unit 130 and the number of alignment errors. Note,however, the control information need not always include all the aboveinformation and may include at least one piece of the above information.

The main control unit 103 is formed from an information processingapparatus (computer), and comprehensively controls the respective unitsof the exposure apparatus 1 via the illumination system control unit108, the projection system control unit 114, and the stage control unit120 in accordance with programs stored in the storage unit 123. The maincontrol unit 103 controls exposure processing of forming a pattern onthe substrate 115 by exposing the substrate 115 via the mask 109. Inaddition, in this embodiment, the main control unit 103 functions as adetermination unit that determines a conveying procedure when conveyingthe substrate 115 between the substrate stage 116 and the conveying unit130 based on control information accumulated in the storage unit 123.

The conveyance of the substrate 115 between the substrate stage 116 andthe conveying unit 130 will be described with reference to FIG. 2. Thesubstrate stage 116 is provided with a chuck 206 that holds thesubstrate 115 on a holding surface. The substrate stage 116 is alsoprovided with lifting pins 205 that are moved up and down by a driveunit (not shown) with respect to the holding surface on which the chuck206 holds the substrate 115. Note that the chuck 206 may be moved up anddown by a drive unit (not shown), instead of the lifting pins 205, tomove the lifting pins 205 up and down relative to the holding surface ofthe chuck 206.

Loading processing concerning the loading of the substrate 115 will bedescribed first. In a device manufacturing factory, the substrate 115 isloaded into the exposure apparatus 1 via the conveying port 201connecting the exposure apparatus 1 to an external apparatus. The firstsubstrate hand 202 conveys the substrate 115 loaded into the exposureapparatus 1 to the pre-alignment unit 203 that performs pre-alignment(coarse positioning) of the substrate 115. The second substrate hand 204conveys the substrate 115 having undergone pre-alignment by thepre-alignment unit 203 to the substrate stage 116. At this time, thesubstrate stage 116 has moved to a substrate loading position (firstposition) in advance. When the second substrate hand 204 transfers thesubstrate 115 to the substrate stage 116, the lifting pins 205 receivefirst the substrate 115 while the lifting pins 205 have risen above theholding surface of the chuck 206. The lifting pins 205 then movedownward to make the chuck 206 hold (transfer) the substrate 115received by the lifting pins 205. The first substrate hand 202, thepre-alignment unit 203, the second substrate hand 204, the lifting pins205, and the chuck 206 each hold the substrate 115 by, for example,vacuum suction. The chuck 206 completes loading processing by holdingthe substrate 115.

Unloading processing concerning the unloading of the substrate 115 willbe described next. When exposure processing for the substrate 115 iscompleted, the substrate stage 116 holding the substrate 115 moves to asubstrate unloading position (first position). When the substrate stage116 transfers the substrate 115 to the first substrate hand 202, thelifting pins 205 move upward first on the substrate stage 116 totransfer the substrate 115 from the chuck 206 to the lifting pins 205.The substrate 115 held by the lifting pins 205 is then transferred tothe first substrate hand 202. The first substrate hand 202 conveys thesubstrate 115 to the conveying port 201. The unloading processing iscompleted by unloading the substrate 115 from the conveying port 201.

First Embodiment

The operation of the exposure apparatus 1 will be described withreference to FIG. 3. In step S101, the exposure apparatus 1 determineswhether a recipe (process) for a target lot (a plurality of substratesincluded in a lot) loaded into the exposure apparatus 1 is the oneprocessed in the past. If the recipe for the target lot is the oneprocessed in the past, the process shifts to step S102. If the recipefor the target lot is not the one processed in the past, the processshifts to step S103.

In step S102, when the same recipe as that for the target lot isprocessed as a conveying procedure at the time of the conveyance of asubstrate 115 between a substrate stage 116 and a conveying unit 130,the exposure apparatus 1 selects the conveying procedure (past conveyingprocedure) stored in a storage unit 123 in association with the recipe.

In step S103, the exposure apparatus 1 selects a conveying procedure(default conveying procedure) set by default as a conveying procedurewhen conveying the substrate 115 between the substrate stage 116 and theconveying unit 130.

In this embodiment, as conveying procedures at the time of theconveyance of the substrate 115 between the substrate stage 116 and theconveying unit 130, a plurality of conveying procedures that can be setfor the substrate stage 116 and the conveying unit 130 are stored in thestorage unit 123. For example, the storage unit 123 stores first andsecond conveying procedures as the plurality of conveying procedures.Assume that in this case, the first conveying procedure (to be referredto as the “productivity-oriented procedure” hereinafter) prioritizesproductivity concerning the conveyance of the substrates 115 more thanthe second conveying procedure. The second conveying procedure (to bereferred to as the “stability-oriented procedure” hereinafter)prioritizes stability concerning the conveyance of the substrates 115more than the first conveying procedure. The default conveying proceduremay be the productivity-oriented procedure. Note that in the embodiment,the plurality of conveying procedures are two types of conveyingprocedures. However, this is not exhaustive. In addition, a defaultconveying procedure may be settable with parameters.

In step S104, the exposure apparatus 1 performs loading processing ofloading the substrate 115 into the exposure apparatus 1. The loadingprocessing is the same as that described with reference to FIG. 2, andhence a detailed description of the processing will be omitted.

In step S105, the exposure apparatus 1 stores, in the storage unit 123,control information concerning the substrate stage 116 and the conveyingunit 130, which is generated as a result of loading the substrate 115.More specifically, the storage unit 123 stores chucking pressures(holding forces) with which lifting pins 205 and a chuck 206 hold thesubstrate 115 and the chucking times required for the lifting pins 205and the chuck 206 to hold the substrate 115 with preset chuckingpressures.

In step S106, the exposure apparatus 1 performs alignment measurementprocessing. The alignment measurement processing is processingconcerning the alignment of the substrate 115 which is performed whenthe substrate 115 is conveyed between the substrate stage 116 and theconveying unit 130. The alignment measurement processing is processingfor measuring a positional shift of the substrate 115. Morespecifically, the alignment measurement processing includes theprocessing of measuring a positional shift between the substrate 115 andthe substrate stage 116 and the processing of measuring a positionalshift between a mask 109 and the substrate 115.

In step S107, the exposure apparatus 1 stores, in the storage unit 123,control information concerning the substrate stage 116 and the conveyingunit 130 which is generated by aligning the substrate 115. Morespecifically, the storage unit 123 stores measurement values concerningthe alignment of the substrate 115 which is performed when the substrate115 is conveyed between the substrate stage 116 and the conveying unit130 and the number of errors in the alignment.

In step S108, the exposure apparatus 1 performs exposure processing offorming a pattern on the substrate 115 by exposing the substrate 115 viathe mask 109 while controlling the relative position between the mask109 and the substrate 115 in accordance with the alignment measurementprocessing performed in step S106.

In step S109, the exposure apparatus 1 performs unloading processing ofunloading the substrate 115 from the exposure apparatus 1. The unloadingprocessing is the same as that described with reference to FIG. 2, andhence a detailed description of the processing will be omitted.

In step S110, the exposure apparatus 1 stores, in the storage unit 123,control information concerning the substrate stage 116 and the conveyingunit 130 which is generated as a result of unloading the substrate 115.More specifically, the storage unit 123 stores chucking pressures(holding forces) with which the lifting pins 205 and the chuck 206 holdthe substrate 115 and the chucking times required for the lifting pins205 and the chuck 206 to hold the substrate 115 with preset chuckingpressures.

In step S111, the exposure apparatus 1 stores information indicatingwhether preset specific errors have occurred. In this case, the specificerrors include, for example, a chucking error, that is, a failure inchucking the substrate 115 by the lifting pins 205 or the chuck 206.

In step S112, the exposure apparatus 1 performs determination processingof determining a conveying procedure when conveying the substrate 115between the substrate stage 116 and the conveying unit 130. The detailsof the determination processing will be described later with referenceto FIG. 4.

In step S113, the exposure apparatus 1 determines whether exposureprocessing has been performed for all the substrates 115 included in alot. If exposure processing has not been performed for all thesubstrates 115 included in the lot, the process shifts to step S104 toperform exposure processing for the next substrate 115. If exposureprocessing has been performed for all the substrates 115 included in thelot, the process shifts to step S114.

In step S114, the exposure apparatus 1 stores, in the storage unit 123,an optimal conveying procedure (that is, the conveying procedureselected in step S102 or S103 or the conveying procedure determined instep S112) for a recipe for the target lot input in step S101 inassociation with the recipe.

The details of determination processing (step S112) of determining aconveying procedure when conveying the substrate 115 between thesubstrate stage 116 and the conveying unit 130 will be described withreference to FIGS. 4A and 4B. In the following description, thethreshold set for each control information accumulated (stored) in thestorage unit 123 is set as the first threshold, and the threshold setfor the number of substrates 115 in the lot which exceed the firstthreshold is set as the second threshold.

In step S201, the exposure apparatus 1 reads out a conveying procedurestored in the storage unit 123. In step S202, the exposure apparatus 1determines whether the chucking pressure and the chucking timeconcerning the chuck 206 in the loading processing which are stored inthe storage unit 123 in step S105 are equal to or less than the firstthresholds set for them. If the chucking force and the chucking timeconcerning the chuck 206 are not equal to or less than the firstthresholds, the process shifts to step S203. If the chucking force andthe chucking time concerning the chuck 206 are equal to or less than thefirst thresholds, the process shifts to step S205.

In step S203, the exposure apparatus 1 counts the number of substrates115 in the lot which exceed the first thresholds in terms of thechucking pressure and the chucking time concerning the chuck 206 in theloading processing. In step S204, the exposure apparatus 1 determineswhether the number of substrates 115 counted in step S203 is equal to orless than the second threshold set for it. If the number of substrates115 counted in step S203 is not equal to or less than the secondthreshold, the process shifts to step S223. If the number of substrates115 counted in step S203 is equal to or less than the second threshold,the process shifts to step S205.

In step S223, the exposure apparatus 1 determines whether the conveyingprocedure is changed (determined) in the lot. If the conveying procedureis not changed in the lot, the process shifts to step S224. If theconveying procedure is changed in the lot, the process shifts to stepS225.

In step S224, the exposure apparatus 1 changes (determines) theconveying procedure and stores the conveying procedure in the storageunit 123. In this embodiment, if, for example, the current conveyingprocedure is a productivity-oriented procedure, the conveying procedureis changed to a stability-oriented procedure for the following reason.If the conveying procedure is a productivity-oriented procedure, it isnecessary to perform recovery processing for an error, resulting in adeterioration in productivity. Accordingly, changing the conveyingprocedure to a stability-oriented procedure prioritizing stability willimprove the productivity. As disclosed in Japanese Patent Laid-Open No.2006-269867, the exposure apparatus 1 may change drive parameters andthe first thresholds concerning the respective units of the substratestage 116 and the conveying unit 130 as well as changing the conveyingprocedure.

In step S225, the exposure apparatus 1 determines whether measurementvalues concerning alignment and the number of errors in alignment exceedthe first thresholds set for them. If the measurement values concerningalignment and the number of errors in alignment exceed the firstthresholds, the process shifts to step S226 to notify the correspondinginformation, for example, information indicating that the error factormay be a process (lot) factor. In other words, if the conveyingprocedure is changed and the measurement values concerning alignment andthe number of errors in alignment do not change before and after thechange in conveying procedure, the exposure apparatus 1 notifies thecorresponding information. Such notification is performed via, forexample, the display or audio output device of the exposure apparatus 1,and hence the display or audio output device functions as a notificationunit.

In step S205, the exposure apparatus 1 determines whether the chuckingpressure and the chucking time concerning the lifting pins 205 inloading processing which are stored in the storage unit 123 in step S105are equal to or less than the first thresholds set for them. If thechucking pressure and the chucking time concerning the lifting pins 205are not equal to or less than the first thresholds, the process shiftsto step S206. If the chucking pressure and the chucking time concerningthe lifting pins 205 are equal to or less than the first thresholds, theprocess shifts to step S208.

In step S206, the exposure apparatus 1 counts the number of substrates115 in the lot which exceed the first thresholds concerning the chuckingpressure and the chucking time concerning the lifting pins 205 in theloading processing. In step S207, the exposure apparatus 1 determineswhether the number of substrates 115 counted in step S206 is equal to orless than the second threshold set for it. If the number of substrates115 counted in step S206 is not equal to or less than the secondthreshold, the process shifts to step S223. If the number of substrates115 counted in step S206 is equal to or less than the second threshold,the process shifts to step S208.

In step S208, the exposure apparatus 1 determines whether the alignmentmeasurement value in alignment measurement processing which is stored inthe storage unit 123 in step S107 is equal to or less than the firstthreshold set for the alignment measurement value. If the alignmentmeasurement value is not equal to or less than the first threshold, theprocess shifts to step S209. If the alignment measurement value is equalto or less than the first threshold, the process shifts to step S211.

In step S209, the exposure apparatus 1 counts the number of substrates115 in the lot which exceed the first threshold concerning the alignmentmeasurement value. In step S210, the exposure apparatus 1 determineswhether the number of substrates 115 counted in step S209 is equal to orless than the second threshold set for the number of substrates. If thenumber of substrates 115 counted in step S209 is not equal to or lessthan the second threshold, the process shifts to step S223. If thenumber of substrates 115 counted in step S209 is equal to or less thanthe second threshold, the process shifts to step S211.

In step S211, the exposure apparatus 1 determines whether an alignmenterror has occurred, based on the number of alignment errors in thealignment measurement processing which is stored in the storage unit 123in step S107. If an alignment error has occurred, the process shifts tostep S212. If no alignment error has occurred, the process shifts tostep S214.

In step S212, the exposure apparatus 1 counts the number of substrates115 in the lot in which alignment errors have occurred concerning thenumber of alignment errors. In step S213, the exposure apparatus 1determines whether the number of substrates 115 counted in step S212 isequal to or less than the second threshold set for the number ofsubstrates. If the number of substrates 115 counted in step S212 is notequal to or less than the second threshold, the process shifts to stepS223. If the number of substrates 115 counted in step S212 is equal toor less than the second threshold, the process shifts to step S214.

In step S214, the exposure apparatus 1 determines whether the chuckingpressure and the chucking time concerning the chuck 206 in the unloadingprocessing which are stored in the storage unit 123 in step S110 areequal to or less than the first thresholds set for them. If the chuckingpressure and the chucking time concerning the chuck 206 are not equal toor less than the first thresholds, the process shifts to step S215. Ifthe chucking pressure and the chucking time concerning the chuck 206 areequal to or less than the first thresholds, the process shifts to stepS217.

In step S215, the exposure apparatus 1 counts the number of substrates115 in the lot which exceed the first threshold concerning the chuckingpressure and the chucking time concerning the chuck 206 in the unloadingprocessing. In step S216, the exposure apparatus 1 determines whetherthe number of substrates 115 counted in step S215 is equal to or lessthan the second threshold. If the number of substrates 115 counted instep S215 is not equal to or less than the second threshold, the processshifts to step S223. If the number of substrates 115 counted in stepS215 is equal to or less than the second threshold, the process shiftsto step S217.

In step S217, the exposure apparatus 1 determines whether the chuckingpressure and the chucking time concerning the lifting pins 205 in theunloading processing which are stored in the storage unit 123 in stepS110 are equal to or less than the first thresholds set for them. If thechucking pressure and the chucking time concerning the lifting pins 205are not equal to or less than the first thresholds, the process shiftsto step S218. If the chucking pressure and the chucking time concerningthe lifting pins 205 are equal to or less than the first thresholds, theprocess shifts to step S220.

In step S218, the exposure apparatus 1 counts the number of substrates115 in the lot which exceed the first thresholds concerning the chuckingpressure and the chucking time concerning the lifting pins 205 in theunloading processing. In step S219, the exposure apparatus 1 determineswhether the number of substrates 115 counted in step S218 is equal to orless than the second threshold set for the number of substrates. If thenumber of substrates 115 counted in step S218 is not equal to or lessthan the second threshold, the process shifts to step S223. If thenumber of substrates 115 counted in step S218 is equal to or less thanthe second threshold, the process shifts to step S220.

In step S220, the exposure apparatus 1 determines whether a specificerror has occurred, based on information indicating the presence/absenceof the specific error which is stored in the storage unit 123 in stepS111. If the specific error has occurred, the process shifts to stepS221. If the specific error has not occurred, the determinationprocessing is terminated.

In step S221, the exposure apparatus 1 counts the number of substrates115 in the lot in which specific errors have occurred. In step S222, theexposure apparatus 1 determines whether the number of substrates 115counted in step S221 is equal to or less than the second threshold setfor the number of substrates. If the number of substrates 115 counted instep S221 is not equal to or less than the second threshold, the processshifts to step S223. Note that with regard to a specific error, theexposure apparatus 1 changes, for example, the first thresholds for thechucking pressures of the chuck 206 and the lifting pins 205 in stepS224. If the number of substrates 115 counted in step S221 is equal toor less than the second threshold, the determination processing isterminated.

A productivity-oriented procedure as one of conveying procedures in thisembodiment will be described with reference to FIG. 5. In step S301, thesubstrate 115 is loaded into the exposure apparatus 1 via a conveyingport 201. In step S302, a first substrate hand 202 conveys (moves) thesubstrate 115 loaded into the exposure apparatus 1 to a pre-alignmentunit 203. In step S303, the pre-alignment unit 203 transfers thesubstrate 115 to the second substrate hand 204. In step S304, thesubstrate 115 is transferred from a second substrate hand 204 to thelifting pins 205 at a substrate loading position.

In step S305, the exposure apparatus 1 moves the second substrate hand204 in the Y-axis minus direction to make the second substrate hand 204retract from the substrate loading position. In step S306, the exposureapparatus 1 moves the substrate stage 116 in the Y-axis plus directionto make the substrate stage 116 retract to a non-interference regionwhere the substrate stage 116 does not interfere with the secondsubstrate hand 204 that has been made to retract in step S305. In stepS307, the exposure apparatus 1 moves the substrate stage 116 in theZ-axis plus direction to drive the substrate stage 116 to a frontinterference region where the substrate stage 116 interferes with thesecond substrate hand 204.

In the productivity-oriented procedure, the exposure apparatus 1concurrently performs steps S305, S306, and S307 in this manner. Inother words, the productivity-oriented procedure is a procedure forconcurrently performing a procedure for making the conveying unit 130retract from the substrate loading position after the conveying unit 130transfers the substrate 115 to the substrate stage 116 at the substrateloading position and a procedure for making the substrate stage 116retract from the substrate loading position. This improves productivityconcerning the loading of substrates 115.

After the completion of the concurrent processing of steps S305, S306,and S307, the lifting pins 205 transfer the substrate 115 to the chuck206 in step S308. Thus, the exposure apparatus 1 terminates theconveying procedure prioritizing productivity.

A stability-oriented procedure as one of the conveying procedures inthis embodiment will be described with reference to FIG. 6. In stepS401, the substrate 115 is loaded into the exposure apparatus 1 via theconveying port 201. In step S402, the first substrate hand 202 conveys(moves) the substrate 115 loaded into the exposure apparatus 1 to thepre-alignment unit 203. In step S403, the pre-alignment unit 203transfers the substrate 115 to the second substrate hand 204. In stepS404, the second substrate hand 204 transfers the substrate 115 to thelifting pins 205 at the substrate loading position.

In step S405, the exposure apparatus 1 moves the second substrate hand204 in the Y-axis minus direction to make the second substrate hand 204retract from the substrate loading position. In step S406, the exposureapparatus 1 moves the substrate stage 116 in the Z-axis plus directionto drive the substrate stage 116 to an interference region where thesubstrate stage 116 interferes with the second substrate hand 204.

In this manner, in the stability-oriented procedure, the exposureapparatus 1 inhibits the movement of the substrate stage 116 while thelifting pins 205 hold the substrate 115. In other words, thestability-oriented procedure is a procedure for sequentially performinga procedure for making the conveying unit 130 retract from the substrateloading position after the conveying unit 130 transfers the substrate115 to the substrate stage 116 at the substrate loading position and aprocedure for making the substrate stage 116 retract from the substrateloading position. This improves stability concerning the loading ofsubstrates 115.

After the completion of the processing in steps S405 and S406, thelifting pins 205 transfer the substrate 115 to the chuck 206 in stepS407. Thus, the exposure apparatus 1 terminates the conveying procedureprioritizing stability.

This embodiment has exemplified the conveying procedure used when thesubstrate 115 is loaded. However, the present invention can also beapplied to a conveying procedure when the substrate 115 is unloaded. Aconveying procedure prioritizing productivity and a conveying procedureprioritizing stability at the time of unloading the substrate 115 willbe described below.

A conveying procedure prioritizing productivity when unloading thesubstrate 115 will be described with reference to FIG. 7. In step S501,the chuck 206 transfers the substrate 115 to the lifting pins 205. Instep S502, the exposure apparatus 1 moves the substrate stage 116 in theZ-axis minus direction to drive the substrate stage 116 to anon-interference region where the substrate stage 116 does not interferewith the first substrate hand 202.

In step S503, the exposure apparatus 1 moves the substrate stage 116 todrive the substrate stage 116 to a substrate unloading position. In stepS504, the exposure apparatus 1 moves the first substrate hand 202 in theY-axis plus direction to drive the first substrate hand 202 to thesubstrate unloading position.

In this manner, in the conveying procedure prioritizing productivity,the exposure apparatus 1 concurrently performs steps S503 and S504. Inother words, this conveying procedure is a procedure for concurrentlyperforming a procedure for moving the substrate stage 116 to thesubstrate unloading position before the conveying unit 130 receives thesubstrate 115 from the substrate stage 116 at the substrate unloadingposition and a procedure for moving the conveying unit 130 to thesubstrate unloading position. This improves productivity concerning theunloading of the substrates 115.

After the completion of the concurrent processing in steps S503 andS504, the lifting pins 205 transfer the substrate 115 to the firstsubstrate hand 202 in step S505. In step S506, the substrate 115 isunloaded from the exposure apparatus 1 through the conveying port 201.Thus, the exposure apparatus 1 terminates the conveying procedureprioritizing productivity when unloading the substrate 115.

A conveying procedure prioritizing stability when unloading thesubstrate 115 will be described with reference to FIG. 8. In step S601,the exposure apparatus 1 moves the substrate stage 116 to drive thesubstrate stage 116 to the substrate unloading position. In step S602,the chuck 206 transfers the substrate 115 to the lifting pins 205. Instep S603, the exposure apparatus 1 moves the substrate stage 116 in theZ-axis minus direction to drive the substrate stage 116 to anon-interference region where the substrate stage 116 does not interferewith the first substrate hand 202. In step S604, the exposure apparatus1 moves the first substrate hand 202 in the Y-axis plus direction todrive the first substrate hand 202 to a substrate conveying position.

In this manner, in the conveying procedure prioritizing stability, theexposure apparatus 1 inhibits the movement of the substrate stage 116while the lifting pins 205 hold the substrate 115. In other words, thisconveying procedure is a procedure for sequentially performing aprocedure for moving the substrate stage 116 to the substrate unloadingposition before the conveying unit 130 receives the substrate 115 fromthe substrate stage 116 at the substrate unloading position and aprocedure for moving the conveying unit 130 to the substrate unloadingposition. This improves stability concerning the unloading of thesubstrates 115.

In step S605, the lifting pins 205 transfer the substrate 115 to thefirst substrate hand 202. In step S606, the substrate 115 is unloadedfrom the exposure apparatus 1 through the conveying port 201. Thus, theexposure apparatus 1 terminates the conveying procedure prioritizingstability when unloading the substrate 115.

In this manner, in this embodiment, the exposure apparatus 1 determines(changes) a conveying procedure when conveying the substrate 115 betweenthe substrate stage 116 and the conveying unit 130 based on controlinformation concerning the substrate stage 116 and the conveying unit130 which is generated as a result of conveying the substrate 115. Inthis case, the exposure apparatus 1 determines a conveying procedurewhen conveying the substrate 115 by selecting one of the plurality ofconveying procedures stored in the storage unit 123 based on eachcontrol information and the result of comparison between each controlinformation and a threshold set for each control information. In theembodiment, while continuously processing the plurality of substrates115 included in the same lot, the exposure apparatus 1 determines aconveying procedure when conveying the substrate 115 between thesubstrate stage 116 and the conveying unit 130. However, the exposureapparatus 1 may also determine a conveying procedure when conveying thesubstrate 115 between the substrate stage 116 and the conveying unit 130for each lot or each preset number of substrates. According to theembodiment, it is possible to automatically determine (change) anoptimal conveying procedure for conveying the substrate 115 between thesubstrate stage 116 and the conveying unit 130 in accordance with aprocess. This makes it possible to improve productivity whilemaintaining stability.

An example of a specific effect of the determination processing shown inFIG. 4 will be described. When, for example, the current chuckingpressure is lower than the chucking pressure stored (accumulated) in thestorage unit 123 or the current chucking time is shorter than thechucking time stored (accumulated) in the storage unit 123, it isestimated that the amount of warpage of the substrate 115 is large orthe flatness of the reverse surface of the substrate 115 is low. Assumethat the exposure apparatus 1 conveys the substrate 115 according to theproductivity-oriented procedure. In this case, when the exposureapparatus 1 moves the substrate stage 116 while the lifting pins 205hold the substrate 115 (step S306), the positional shift of thesubstrate 115 can occur. In addition, the substrate 115 may drop fromthe lifting pins 205. In such a case, the exposure apparatus 1 selectsthe stability-oriented procedure because the stability-orientedprocedure can improve productivity concerning the conveyance of thesubstrates 115 more than the productivity-oriented procedure.

A measurement value concerning alignment and the number of errors inalignment are used when the chucking pressure and the chucking time aresimilar to the chucking pressure and the chucking time stored(accumulated) in the storage unit 123. If the measurement valueconcerning alignment is an abnormal value or an alignment error hasoccurred, it is estimated that the contact surface between the substrate115 and the lifting pins 205 has been contaminated or physicallydefected. In such a case, the exposure apparatus 1 selects thestability-oriented procedure because the stability-oriented procedurecan improve productivity concerning the conveyance of the substrates 115more than the productivity-oriented procedure.

The exposure apparatus 1 may further include a user interface 150 thatprovides the user with a setting screen for setting first and secondthresholds. FIG. 9 shows an example of a setting screen 701 for settingfirst and second thresholds which is provided (displayed) on a displayor touch panel as the user interface 150. A main control unit 103provides the user interface 150.

On the setting screen 701, a parameter 702 serves to set the firstthreshold for the chucking pressure of the chuck 206 in loadingprocessing. A parameter 703 serves to set the second thresholdconcerning the number of substrates 115 for each of which the chuckingpressure of the chuck 206 in loading processing exceeds the firstthreshold. A parameter 704 serves to set a conveying procedure to bedetermined (changed) when the second threshold is exceeded in the samelot.

A parameter 705 serves to set the first threshold for the chucking timeof the chuck 206 in loading processing. A parameter 706 serves to setthe second threshold concerning the number of substrates 115 for each ofwhich the chucking time of the chuck 206 in loading processing exceedsthe first threshold. A parameter 707 serves to set a conveying procedureto be determined (changed) when the second threshold is exceeded in thesame lot.

A parameter 708 serves to set the first threshold for the chuckingpressure of the lifting pins 205 in loading processing. A parameter 709serves to set the second threshold concerning the number of substrates115 for each of which the chucking pressure of the lifting pins 205 inloading processing exceeds the first threshold. A parameter 710 servesto set a conveying procedure to be determined (changed) when the secondthreshold is exceeded in the same lot.

A parameter 711 serves to set the first threshold for the chucking timeof the lifting pins 205 in loading processing. A parameter 712 serves toset the second threshold concerning the number of substrates 115 foreach of which the chucking time of the lifting pins 205 in loadingprocessing exceeds the first threshold. A parameter 713 serves to set aconveying procedure to be determined (changed) when the second thresholdis exceeded in the same lot.

A parameter 714 serves to set the first threshold for measurement valuesconcerning alignment. Note that a plurality of first thresholds may beset for measurement values concerning alignment. For example, the firstthresholds may be respectively set for the X-axis, the Y-axis, and therotational axis. A parameter 715 serves to set the second thresholdconcerning the number of substrates 115 for each of which a measurementvalue concerning alignment exceeds the first threshold. A parameter 716serves to set a conveying procedure to be determined (changed) when thesecond threshold is exceeded in the same lot.

A parameter 717 serves to set the second threshold for the number ofalignment errors. A parameter 718 serves to set a conveying procedure tobe determined (changed) when the second threshold is exceeded in thesame lot.

A parameter 719 serves to set the first threshold for the chuckingpressure of the chuck 206 in unloading processing. A parameter 720serves to set the second threshold concerning the number of substrates115 for each of which the chucking pressure of the chuck 206 inunloading processing exceeds the first threshold. A parameter 721 servesto set a conveying procedure to be determined (changed) when the secondthreshold is exceeded in the same lot.

A parameter 722 serves to set the first threshold for the chucking timeof the chuck 206 in unloading processing. A parameter 723 serves to setthe second threshold concerning the number of substrates 115 for each ofwhich the chucking time of the chuck 206 in unloading processing exceedsthe first threshold. A parameter 724 serves to set a conveying procedureto be determined (changed) when the second threshold is exceeded in thesame lot.

A parameter 725 serves to set the first threshold for the chuckingpressure of the lifting pins 205 in unloading processing. A parameter726 serves to set the second threshold concerning the number ofsubstrates 115 for each of which the chucking pressure of the liftingpins 205 in unloading processing exceeds the first threshold. Aparameter 727 serves to set a conveying procedure to be determined(changed) when the second threshold is exceeded in the same lot.

A parameter 728 serves to set the first threshold for the chucking timeof the lifting pins 205 in unloading processing. A parameter 729 servesto set the second threshold concerning the number of substrates 115 foreach of which the chucking time of the lifting pins 205 in unloadingprocessing exceeds the first threshold. A parameter 730 serves to set aconveying procedure to be determined (changed) when the second thresholdis exceeded in the same lot.

A parameter 731 serves to set an error number corresponding to aspecific error. A parameter 732 serves to set the second thresholdconcerning the number of substrates 115 having undergone a specificerror. A parameter 733 serves to set a conveying procedure to bedetermined (changed) when the second threshold is exceeded in the samelot.

A parameter 734 serves to set a default conveying procedure.

Second Embodiment

The first embodiment has exemplified the case in which a conveyingprocedure is determined (changed) by using each threshold set for eachpiece of control information. However, this is not exhaustive. Forexample, a conveying procedure may be determined (changed) by using alearning model obtained by machine learning.

In the second embodiment, first of all, learning data indicating therelationship between input data and teacher data is prepared. In thiscase, the input data is data including at least one of a measurementvalue concerning a chucking pressure, chucking time, or alignment andthe number of alignment errors. The teacher data is data indicating aproper conveying procedure for input data. The data indicating a properconveying procedure can be data indicating two values respectivelyrepresenting being proper and improper. Note that as data indicating aproper conveying procedure, data indicating a value (for example, anatural number from 1 to 10) representing a stepwise evaluation ofproperness or data indicating the probability (for example, a realnumber from 0 to 1) of being proper.

It is possible to obtain input data such as measurement valuesconcerning chucking pressures, chucking times, and alignment and thenumber of alignment errors by usual substrate processing. A conveyingprocedure as output data can be derived by calculating statistics fromeach input data (control information) accumulated in a storage unit 123and productivity. It is also possible to derive a conveying procedurefrom an experiment of obtaining each input data by processing varioustypes of substrates 115 and comparing productivities.

A learning model for determining a proper conveying procedure isobtained by using learning data. Learning data can be obtained by using,for example, a neural network. The neural network is a model having amultilayer network structure including an input layer, an intermediatelayer, and an output layer. It is possible to obtain a learning data byoptimizing random variables inside the network by an algorithm such as abackpropagation method using learning data indicating the relationshipbetween input data and teacher data. This embodiment has exemplified thecase in which a learning model is obtained by using a neural network.However, this is not exhaustive. For example, other models andalgorithms such as a support vector machine and a determination tree maybe used.

Inputting new input data to the obtained learning model will output dataindicating a proper conveying procedure as output data. A properconveying procedure can be determined based on the output data.

Note that the first embodiment and the second embodiment can beselectively executed. In other words, setting can be made to determine aconveying procedure by using each threshold set for each piece ofcontrol information or determine a conveying procedure by using thelearning model obtained by machine learning. For example, as shown inFIG. 10, two checkboxes 741 and 742 are provided on the setting screen701 provided on the user interface 150. The checkbox 741 is a checkboxfor selecting to determine a conveying procedure by using eachthreshold. The checkbox 742 is a checkbox for selecting to determine aconveying procedure by using a learning model.

Third Embodiment

An article manufacturing method according to an embodiment of thepresent invention is suitable for manufacturing an article, for example,a device (a semiconductor device, magnetic storage medium, liquidcrystal element, or the like). This manufacturing method includes a stepof forming a pattern on a substrate by using the exposure apparatus 1, astep of processing the substrate on which the pattern is formed, and astep of manufacturing an article from the processed substrate. Thismanufacturing method further includes other known steps (oxidation,deposition, vapor deposition, doping, planarization, etching, resistremoval, dicing, bonding, packaging, and the like). The articlemanufacturing method according to this embodiment is advantageous in atleast one of the performance, the quality, the productivity, and theproduction cost of the article, as compared to a conventional method.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent application No.2019-048747 filed on Mar. 15, 2019, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A substrate processing apparatus for processing asubstrate, the apparatus comprising: a stage configured to hold and movethe substrate; a conveying unit configured to hold and convey thesubstrate between conveying unit and the stage; an accumulation unitconfigured to accumulate control information concerning the stage andthe conveying unit which is generated by processing the substrate; and adetermination unit configured to determine a conveying procedure whenconveying the substrate between the stage and the conveying unit byselecting one of a plurality of conveying procedures which can be setfor the stage and the conveying unit based on control informationaccumulated in the accumulation unit.
 2. The apparatus according toclaim 1, further comprising a storage unit configured to store theplurality of conveying procedures, wherein the determination unitdetermines a conveying procedure when conveying the substrate byselecting one of the plurality of conveying procedures stored in thestorage unit based on control information accumulated in theaccumulation unit.
 3. The apparatus according to claim 1, wherein theplurality of conveying procedures include a first conveying procedureand a second conveying procedure, the first conveying procedure is aconveying procedure prioritizing productivity concerning conveyance ofthe substrate more than the second conveying procedure, and the secondconveying procedure is a conveying procedure prioritizing stabilityconcerning conveyance of the substrate more than the first conveyingprocedure.
 4. The apparatus according to claim 3, wherein the firstconveying procedure is a procedure for concurrently performing aprocedure for making the conveying unit transfer the substrate to thestage at a first position and then making the conveying unit retractfrom the first position and a procedure for making the stage retractfrom the first position, and the second conveying procedure is aprocedure for sequentially performing a procedure for making theconveying unit transfer the substrate to the stage at the first positionand then making the conveying unit retract from the first position and aprocedure for making the stage retract from the first position.
 5. Theapparatus according to claim 3, wherein the first conveying procedure isa procedure for concurrently performing a procedure for moving the stageto a first position before the conveying unit receives the substratefrom the stage at the first position and a procedure for moving theconveying unit to the first position, and the second conveying procedureis a procedure for sequentially performing a procedure for moving thestage to the first position before the conveying unit receives thesubstrate from the stage at the first position and a procedure formoving the conveying unit to the first position.
 6. The apparatusaccording to claim 1, wherein the control information includes at leastone of a holding force with which each of the stage and the conveyingunit holds the substrate, a time required for each of the stage and theconveying unit to hold the substrate with a preset holding force, ameasurement value concerning alignment of the substrate which isperformed when the substrate is conveyed between the stage and theconveying unit, and the number of errors in the alignment.
 7. Theapparatus according to claim 6, wherein the determination unitdetermines a conveying procedure when conveying the substrate betweenthe stage and the conveying unit based on a result of comparing each ofthe holding force, the time, the measurement value, and the number oferrors and a threshold set for each of the holding force, the time, themeasurement value, and the number of errors.
 8. The apparatus accordingto claim 7, further comprising a user interface configured to provide auser with a setting screen for setting the threshold.
 9. The apparatusaccording to claim 1, wherein the substrate processing apparatuscontinuously processes a plurality of substrates included in the samelot, and the determination unit determines a conveying procedure whenconveying the substrate between the stage and the conveying unit whilethe plurality of substrates are continuously processed.
 10. Theapparatus according to claim 9, further comprising a notification unitconfigured to notify, when a conveying procedure is changed at a time ofconveying the substrate between the stage and the conveying unit duringcontinuous processing of the plurality of substrates and no changeoccurs in a measurement value concerning alignment of the substrate,which is performed at a time of conveying the substrate between thestage and the conveying unit, and the number of errors in the alignmentbefore and after the change of the conveying procedure, correspondinginformation.
 11. The apparatus according to claim 1, further comprisinga projection optical system configured to project an image of a maskpattern on the substrate held by the stage.
 12. An article manufacturingmethod comprising: forming a pattern on a substrate by using a substrateprocessing apparatus defined in claim 1; processing the substrate onwhich the pattern is formed in the forming; and manufacturing an articlefrom the processed substrate.